The present invention relates to a method of changing the construction of a logical volume area in a storage and, more particularly, a method of expanding a logical volume area.
Conventionally, as a method of expanding the capacity in a storage, an expansion method by adding a physical disk is known. The method will be described with reference to FIG. 15. Reference numeral 100 denotes a storage and 101 indicates a physical disk area as a collection of physical disks. In the physical disk area 101, logical volumes called LU (Logical Units) designated by reference numerals 1011x (1011a, 1011b, . . . ) are constructed. In the case of expanding the capacity of the storage, by adding a physical disk to the storage 100, as shown by a broken line, an added disk area 102 is generated. When the logical volumes LU1 (1011a) and LU2 (1011b) in the physical disk area 101 become full, a new logical volume LU3 (1011c) can be generated in the added disk area 102.
However, in the case of expanding the area of an internal logical volume already allocated to increase the usable capacity of the storage, a problem occurs. For example, in the case of enlarging the LU1 (1011a) in FIG. 15, since the LU2 (1011b) immediately follows, the LU2 (1011b) has to be released. In order to enlarge the logical volume area in the storage 100, the area has to be released once and allocation of the logical volume area has to be newly defined. Consequently, an access to a logical volume has to be interrupted.